/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
* (C) 2017 by Argonne National Laboratory.
* See COPYRIGHT in top-level directory.
*/
#include "mpiimpl.h"
/*
* Linear
*
* Linear algorithm where the root sends to each process individually.
*
* Cost: p.alpha + n.beta
*/
#undef FUNCNAME
#define FUNCNAME MPIR_Iscatter_sched_inter_linear
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Iscatter_sched_inter_linear(const void *sendbuf, int sendcount, MPI_Datatype sendtype,
void *recvbuf, int recvcount, MPI_Datatype recvtype, int root,
MPIR_Comm * comm_ptr, MPIR_Sched_t s)
{
int mpi_errno = MPI_SUCCESS;
int remote_size;
int i;
MPI_Aint extent;
if (root == MPI_PROC_NULL) {
/* local processes other than root do nothing */
goto fn_exit;
}
remote_size = comm_ptr->remote_size;
if (root == MPI_ROOT) {
MPIR_Datatype_get_extent_macro(sendtype, extent);
for (i = 0; i < remote_size; i++) {
mpi_errno =
MPIR_Sched_send(((char *) sendbuf + sendcount * i * extent), sendcount, sendtype, i,
comm_ptr, s);
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
}
MPIR_SCHED_BARRIER(s);
} else {
mpi_errno = MPIR_Sched_recv(recvbuf, recvcount, recvtype, root, comm_ptr, s);
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
MPIR_SCHED_BARRIER(s);
}
fn_exit:
return mpi_errno;
fn_fail:
goto fn_exit;
}